I didn’t intend to do this, but I seem to have something of a theme going this week. The last three movies I’ve reviewed— The Incubus, I Married a Monster from Outer Space, and now Inseminoid/Horror Planet— all hinge on the same central idea: unearthly beings screwing human women. (Come to think of it, there was a little bit of that in The Legend of Hell House, too.) This first-generation English Alien rip-off is more than a little hard to follow, but it is as compelling as it is confusing, with first and final acts that move at the breathless pace of a 70’s kung fu movie (not altogether surprising when you consider that Inseminoid was presented by Sir Run Run Shaw, who was just then wrapping up his storied career as the Jim Nicholson of Hong Kong).

Here’s the setup: An archaeological expedition under the aegis of an agency called Xenia is conducting a dig on a distant planet with the aim of learning what caused the extinction of the comparatively advanced civilization that once inhabited it. In particular, the team is investigating what appears to be an ancient tomb dug into the base of a forbidding cliff-face. The expedition has been going well thus far, but things turn very bad when team members Dean (Dominic Jephcott) and Ricky (David Baxt, whose brief appearance in The Shining you’ll miss if you aren’t paying close attention) force their way past a wall inscribed with mysterious hieroglyphics into a hidden chamber filled with strange crystals. Without warning, something in the chamber explodes, badly burning Dean, and shocking him into a deep coma. Ricky is hurt, too, but he at least remains semi-conscious, and Karl, the dig’s medic (Barry Houghton), is able to patch him up. Though nobody was killed in the blast, mission chief Holly (Jennifer Ashley, from Chained Heat and Tintorera) suspends all operations in the newly opened section of the tomb until she has some idea what caused the explosion in the first place.

Unexplained explosions are the least of the archaeologists’ worries. Mitch the chemist (Trevor Thomas, from Transmutations and Sheena) can’t figure out what the crystals Ricky brought in from the tomb are, but he’s sure of one thing— they’re suffused with some kind of bioenergy field. And even more troubling, strange things begin to happen to anyone who ventures into the tomb. They seem to lose their wits; one, a woman named Gwen (Rosalind Lloyd), gets her foot caught between pieces of debris just outside the lab compound’s airlock, and becomes so flustered that she accidentally breaks some of the life-support equipment on her space suit. Eventually, her spiraling panic completely overcomes her judgement, and she tries to free herself by amputating her own foot with a chainsaw-like device she had been carrying. Needless to say, she bleeds to death before anyone can come to her aid. And at about the same time, Ricky regains full consciousness, and completely flips out. He straps on a space suit and heads straight for the off-limits part of the tomb, almost as though he were answering some kind of call from inside it. He then begins attacking his teammates, and Kate, the team reporter (Stephanie Beacham, of And Now the Screaming Starts and Schizo) is forced to shoot him in self-defense. Finally, something else— something not human— attacks and kills Mitch, and abducts a woman named Sandy (Judy Geeson, from Dominique is Dead and It’s Not the Size That Counts). In one of the most baffling scenes in the movie, this creature rapes Sandy, and then leaves her where her coworkers are sure to find her.

A subsequent medical examination reveals that Sandy is pregnant— about two months’ worth, in fact— though such a thing ought not to be possible, because all the women on the mission were given injections of birth-control drugs before embarking for the planet. Soon, whatever is gestating inside Sandy begins changing her to suit its own ends. She becomes superhumanly strong and tough, and begins killing off her comrades and eating their viscera. As the body count rises, she also begins destroying the compound’s equipment, until only four members of the team— Mark (Robin Clarke), Gary (Steven Grives, of A Nightmare on Elm Street 5: The Dream Child), Kate, and Sharon (Heather Wright, who had earlier been a featured extra in Psychomania)— remain, trapped in what’s left of the operations room. The eventual birth of Sandy’s hybrid twins only makes matters worse. This is another of those rare films in which anyone can die at any time.

What fascinates me the most about Inseminoid is the fact that it does not so much copy Alien, per se, but rather Dan O’Bannon’s original script for that movie (from which the finished film diverged in a number of important respects). Most striking is the moment early on in which Dean and Ricky discover the ancient hieroglyphic text inscribed on the wall of the tomb shortly before they inadvertently unleash the Inseminoid and seal their own doom. The original script for Alien had the Nostromo crew discovering a ruined pyramid on the planet’s surface, on which a warning had been carved in indecipherable pictographic writing. It was in this pyramid, and not beneath the wreck of the alien spacecraft, that the crew was to have stumbled upon the egg hatchery. Also of note are a few scenes that seem to prefigure an equally sleazy American Alien clone, Forbidden World/Mutant; I’m thinking in particular of Mitch and Karl’s efforts to figure out what’s generating the bioenergy in the crystals Dean and Ricky brought back from the tomb, which strongly remind me of certain laboratory sequences from the latter movie. Finally, there’s even a subtle allusion to The Angry Red Planet. Note how the planet’s atmosphere is shown glowing red by day, and blue by night. Whatever else it may be, Inseminoid is certainly in touch with its cinematic heritage.